1 /* vi: set sw=4 ts=4: */
3 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
6 //config: bool "passwd (21 kb)"
8 //config: select FEATURE_SYSLOG
10 //config: passwd changes passwords for user and group accounts. A normal user
11 //config: may only change the password for his/her own account, the super user
12 //config: may change the password for any account. The administrator of a group
13 //config: may change the password for the group.
15 //config: Note that busybox binary must be setuid root for this applet to
16 //config: work properly.
18 //config:config FEATURE_PASSWD_WEAK_CHECK
19 //config: bool "Check new passwords for weakness"
21 //config: depends on PASSWD
23 //config: With this option passwd will refuse new passwords which are "weak".
25 //applet:/* Needs to be run by root or be suid root - needs to change /etc/{passwd,shadow}: */
26 //applet:IF_PASSWD(APPLET(passwd, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
28 //kbuild:lib-$(CONFIG_PASSWD) += passwd.o
30 //usage:#define passwd_trivial_usage
31 //usage: "[OPTIONS] [USER]"
32 //usage:#define passwd_full_usage "\n\n"
33 //usage: "Change USER's password (default: current user)"
35 //usage: "\n -a ALG "CRYPT_METHODS_HELP_STR
36 //usage: "\n -d Set password to ''"
37 //usage: "\n -l Lock (disable) account"
38 //usage: "\n -u Unlock (enable) account"
43 static char* new_password(const struct passwd *pw, uid_t myuid, const char *algo)
45 char salt[MAX_PW_SALT_LEN];
46 char *orig = (char*)"";
49 char *ret = NULL; /* failure so far */
51 if (myuid != 0 && pw->pw_passwd[0]) {
54 orig = bb_ask_noecho_stdin("Old password: "); /* returns ptr to static */
57 encrypted = pw_encrypt(orig, pw->pw_passwd, 1); /* returns malloced str */
58 if (strcmp(encrypted, pw->pw_passwd) != 0) {
59 syslog(LOG_WARNING, "incorrect password for %s", pw->pw_name);
60 bb_do_delay(LOGIN_FAIL_DELAY);
61 puts("Incorrect password");
64 if (ENABLE_FEATURE_CLEAN_UP)
67 newp = bb_ask_noecho_stdin("New password: "); /* returns ptr to static */
70 if (ENABLE_FEATURE_PASSWD_WEAK_CHECK
71 && obscure(orig, newp, pw)
74 goto err_ret; /* non-root is not allowed to have weak passwd */
77 cp = bb_ask_noecho_stdin("Retype password: ");
80 if (strcmp(cp, newp) != 0) {
81 puts("Passwords don't match");
85 crypt_make_pw_salt(salt, algo);
87 /* pw_encrypt returns malloced str */
88 ret = pw_encrypt(newp, salt, 1);
93 if (ENABLE_FEATURE_CLEAN_UP) free(orig);
96 if (ENABLE_FEATURE_CLEAN_UP) free(newp);
99 if (ENABLE_FEATURE_CLEAN_UP) free(cp);
103 int passwd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
104 int passwd_main(int argc UNUSED_PARAM, char **argv)
107 OPT_algo = (1 << 0), /* -a - password algorithm */
108 OPT_lock = (1 << 1), /* -l - lock account */
109 OPT_unlock = (1 << 2), /* -u - unlock account */
110 OPT_delete = (1 << 3), /* -d - delete password */
111 OPT_lud = OPT_lock | OPT_unlock | OPT_delete,
115 const char *opt_a = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
116 const char *filename;
122 struct rlimit rlimit_fsize;
124 #if ENABLE_FEATURE_SHADOWPASSWDS
125 /* Using _r function to avoid pulling in static buffers */
130 logmode = LOGMODE_BOTH;
131 openlog(applet_name, 0, LOG_AUTH);
132 opt = getopt32(argv, "a:lud", &opt_a);
137 /* -l, -u, -d require root priv and username argument */
138 if ((opt & OPT_lud) && (myuid != 0 || !argv[0]))
141 /* Will complain and die if username not found */
142 myname = xstrdup(xuid2uname(myuid));
143 name = argv[0] ? argv[0] : myname;
145 pw = xgetpwnam(name);
146 if (myuid != 0 && pw->pw_uid != myuid) {
148 bb_error_msg_and_die("%s can't change password for %s", myname, name);
151 #if ENABLE_FEATURE_SHADOWPASSWDS
153 /* getspnam_r may return 0 yet set result to NULL.
154 * At least glibc 2.4 does this. Be extra paranoid here. */
155 struct spwd *result = NULL;
157 if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) != 0
158 || !result /* no error, but no record found either */
159 || strcmp(result->sp_namp, pw->pw_name) != 0 /* paranoia */
161 if (errno != ENOENT) {
163 bb_perror_msg("no record of %s in %s, using %s",
164 name, bb_path_shadow_file,
165 bb_path_passwd_file);
167 /* else: /etc/shadow does not exist,
168 * apparently we are on a shadow-less system,
169 * no surprise there */
171 pw->pw_passwd = result->sp_pwdp;
176 /* Decide what the new password will be */
178 c = pw->pw_passwd[0] - '!';
179 if (!(opt & OPT_lud)) {
180 if (myuid != 0 && !c) { /* passwd starts with '!' */
182 bb_error_msg_and_die("can't change "
183 "locked password for %s", name);
185 printf("Changing password for %s\n", name);
186 newp = new_password(pw, myuid, opt_a);
188 logmode = LOGMODE_STDIO;
189 bb_error_msg_and_die("password for %s is unchanged", name);
191 } else if (opt & OPT_lock) {
193 goto skip; /* passwd starts with '!' */
194 newp = xasprintf("!%s", pw->pw_passwd);
195 } else if (opt & OPT_unlock) {
197 goto skip; /* not '!' */
198 /* pw->pw_passwd points to static storage,
199 * strdup'ing to avoid nasty surprizes */
200 newp = xstrdup(&pw->pw_passwd[1]);
201 } else if (opt & OPT_delete) {
205 rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * 30000;
206 setrlimit(RLIMIT_FSIZE, &rlimit_fsize);
215 #if ENABLE_FEATURE_SHADOWPASSWDS
216 filename = bb_path_shadow_file;
217 rc = update_passwd(bb_path_shadow_file, name, newp, NULL);
219 /* password in /etc/shadow was updated */
222 /* 0 = /etc/shadow missing (not an error), >0 = passwd changed in /etc/shadow */
225 filename = bb_path_passwd_file;
226 rc = update_passwd(bb_path_passwd_file, name, newp, NULL);
230 bb_error_msg_and_die("can't update password file %s", filename);
231 bb_error_msg("password for %s changed by %s", name, myname);
233 /*if (ENABLE_FEATURE_CLEAN_UP) free(newp); - can't, it may be non-malloced */
236 bb_error_msg_and_die("password for %s is already %slocked",
237 name, (opt & OPT_unlock) ? "un" : "");
240 if (ENABLE_FEATURE_CLEAN_UP)